Effects of workbook training using editorials and newspaper articles in adults with preclinical stage of dementia

Early detection and intervention in individuals in the pre-clinical stage of dementia are crucial. This study aimed to examine whether there are significant differences in (1) word retrieval, (2) subjective communication ability, (3) intervention satisfaction through the 'Fill-in-the-blanks in editorial and newspaper articles' training in patients with subjective cognitive decline and mild cognitive impairment corresponding to the pre-clinical stage of dementia. Ninety-nine patients (50 in the intervention group and 49 in the control group) aged 50–84 years were administered pre- and post-test after 6 weeks of intervention (30 sessions). Regarding word retrieval, there were significant intervention effects on confrontation naming, semantic fluency, and phonemic fluency. The majority of participants in the intervention group were highly satisfied with the training. In terms of intervention satisfaction, the majority of the participants in the intervention group showed high satisfaction with all the questions. This result confirmed the improvement of word retrieval ability through mass communication content-based 'Fill-in-the-blanks' training, and ultimately helps to provide a clinical basis for applying this intervention to prevent dementia.


Participants
Using the F-test using the G*power 3.1.9.2 program, we found that a sample size of more than 92 people was an appropriate number of participants at effect size 0.15, significance level 0.05, and power 80%.The sample was consecutively selected among patients who visited the neurology department of the general hospital.This study involved 99 adults (50 in the intervention group and 49 in the control group) aged 50-84 years who were in the preclinical stage of dementia.Diagnosis was perfomed by a neurologist based on a neurological examination and a review of the patients' medical history.All participants included met the criteria for selection and provided informed consent.The recruited participants were assigned a number according to random ordering (randomized control trial design).Those assigned odd numbers were included in the intervention group and even numbers were included in the control group.All participants participated in the entire process with a 0% drop-out rate.
The 99 participants included 50 adults diagnosed with SCD (25 each in the intervention and control group) and 49 adults diagnosed with MCI (25 patients in the intervention group and 24 patients in the control group).The MCI group included 39 aMCI and 10 naMCI patients.As the preliminary step for the study, we compared specific characteristics (age, education, and SGDS) of the SCD and MCI groups.An independent sample t test was conducted to assess differences in the characteristics between the SCD and MCI groups, and there were no significant differences in age (t = − 0.551, p = 0.583), number of years of education (t = 0.247, p = 0.805), and SGDS scores (t = − 0.117, p = 0.907).In addition, independent sample t-tests were conducted to investigate the differences between the intervention and control groups in the SCD and MCI groups.We found that there were no significant differences in the demographic information of the intervention and control groups in the SCD and MCI groups.These preliminary results are presented in the Appendix.Based on this homogeneity, we combined the two groups and termed the group the 'preclinical stage of Alzheimer's type dementia.' Between the experimental and control groups, there were no significant differences in age (t = 0.646, p = 0.520), years of education (t = − 0.171, p = 0.864), K-MMSE (t = − 1.552, p = 0.124), or SGDS (t = 0.040, p = 0.969) scores.Data on participant characteristics are presented in Table 1.

Intervention materials
The 'workbook using editorial and newspaper articles' training is for middle-aged adults who are in the preclinical stage with mild symptoms before AD progression.It is designed to improve word retrieval by utilizing context while gaining knowledge about life through the latest editorials and newspaper articles.Hence, it is a self-intervention training program developed to improve functional communication and quality of life in terms of word retrieval.The main training format of this program was the 'fill-in-the-blanks' task, which was borrowed from the format of the sentence completion task, one of the naming tasks of the Korean-Western Aphasia Battery(K-WAB) 28 (e.g.roses are red and forsythia is____?).For the fill-in-the-blanks task, the researcher selected major articles and editorials on the front page of a newspaper among articles published in newspapers within the last year.It was created by abbreviating articles between 400 and 600 letters and making blanks by selecting 10 keywords per passage.The difficulty of the words in the blanks was divided into thirds according to the standard of 'Contemporary Korean Use Frequency Survey 2' of the National Institute of the Korean Language 29 , and words with a frequency of 66% or less were selected as middle and low frequencies.The text source was indicated at the bottom of each task.The workbook consisted of material for 30 days (6 weeks, 5 days a week), and two fingerprints (one editorial and newspaper article each) were included in the one-day supply.The total number of words in the workbook was 600.The first chapter of the workbook is created by printing text including the blanks to be filled in by the participants themselves.In the second chapter, the initial consonant and semantic cues of the target words corresponding to each blank are presented for naming using cues as much as possible in a situation where self-intervention training cannot help in filling in the blanks.Definitions from the Korean Standard Dictionary 30 were used as semantic cues.After creating the workbook, a Likert scale ranging from 1 to 5 points (1 = Very inappropriate. 2 = Not appropriate, 3 = Moderate, 4 = Appropriate, 5 = Very appropriate) was used to assess the appropriateness of the content and tasks for improving word extraction ability.Three certified speech-language pathologists (SLPs) with doctorate degrees in speech-language pathology evaluated eight items of the validity of the workbook.The mean value of all items was greater than the 4.3 point, signifying the content and tasks were appropriate.
Two naming tasks (letter completion according to semantic category and word generation using initial consonants) were used as additional training tasks.In the letter completion task, a letter is completed by looking at the phoneme presented after a semantic category (for example, This is a word related to 'animal' .Complete the letters).In the word generation task using the initial consonant, two consecutive consonants are presented initially and using these consonants, the participants need to write down ≥ 10 meaningful words (e.g.Write 10 words that start with ' ' ').' ').The procedure for performing the task was presented at the beginning of the workbook.The researcher reviewed the procedure for approximately 5 to 10 min, demonstrated it orally, and explained how to solve the workbook to the participants, to confirm the participants' familiarity with the training method.

Intervention procedures
This intervention was conducted as a self-intervention method for 30 sessions, five days per week over 6 weeks.The workbook was handed out by the researcher directly to the intervention group that had completed the pretest.Initially, the participants had 5 to 10 min to review, demonstrate, and explain orally the method to solve the workbook.Their level of familiarity with the training method was also confirmed.During the workbook implementation period, the following instructions were provided: "(1) Please complete the workbook regularly from Monday to Friday.If you cannot solve it for personal reasons, please extend it to weekends.(2) We will text you daily to ensure that you have completed your workbook.Kindly reply.(3) If you are unsure how to solve the workbook, you can contact us by phone at any time.(4) Please be honest in terms of solving the workbook." For effective self-intervention, the researcher contacted the participants using text messages and phones every day during the training period.When the task was not completed within a set time, a text message was sent to encourage the participants to complete the task.The average task performance time per session was 40-50 min.
The workbook was used as follows: First, the participants were asked to read the editorial and newspaper articles aloud on the right page and write the appropriate words in the blanks.Unknown answers were left blank.On the next page, the semantic and phonemic cues of the target word were presented, for filling in the blanks.www.nature.com/scientificreports/Third, the intervention group was asked to complete the letter completion task and initial consonant word task of the subtasks on the right page.For the letter completion and initial consonant word tasks, a separate correct answer sheet was provided for filling in the correct answer with a different colored ballpoint pen for the wrong questions.Subsequently, by presenting the correct answer in the last chapter, the participant repeated reading the text aloud, returned to the fill-in-the-blanks task in the first chapter, and remembered the answer without looking at the correct answer to fill in the remaining blanks.After completing the workbook, the intervention group visited the hospital within a week to submit the workbook and undergo a post-test, which was conducted only for the intervention group participants, who completed the workbook.In addition, during the post-test, feedback on the benefits and challenges associated with the workbook was obtained.The control group participated only in the pre-post test without self-intervention training.Approval was granted by the Ethics Committee of Institutional Review Board of Samsung Medical Center (#2020-03-017-003).Confirms that all experiments were performed in accordance with relevant named guidelines and regulations.The procedures used in this study adhere to the tenets of the Declaration of Helsinki.

Instruments
With respect to the inclusion and selection of participants, the following criteria and screening tests were used to select adults with the preclinical stage of dementia.The SCD participants (1) had no history of mental and neurological disease on the health screening questionnaire 31 , (2) complained of memory impairment and scored ≥ 25 in the Memory Age associated Complaint-Questionnaire 32 , (3) had scores within or greater than the sixteeth percentile on the Korean-Mini Mental State Examination (K-MMSE) 33 and Seoul Neuropsychological Screening Battery (SNSB-II) 34 (as a standardized test designed to comprehensively evaluate the five cognitive domains: Attention, Language & Related Functions, Visuospatial Functions, Memory, Frontal/Executive Function), ( 4) had no depression with a score ≤ 8 on the Short Form Geriatric Depression Scale (SGDS) 35 , and (5) had recived education above middle school level.The MCI participants were diagnosed by a neurologist using the criteria of Petersen 10 based on a neurological examination and medical history.The detailed criteria are as follows: The MCI participants (1) scored 0.5 on the clinical dementia rating (CDR), (2) had the subjective memory impairment complaint by the person or guardian, (3) scored within or greater than the sixteeth percentile on K-MMSE, and had normal overall cognitive function ( 4) had scores within or greater than the sixteeth percentile based on age and years of education of the SNSB-II 34 as objective memory impairment, but had no difficulty in performing daily-life activities by scoring < 8 on the Seoul-Instrumental Activities of Daily Living; S-IADL) 36 , ( 5) did not correspond to the criteria for dementia, and (6) were with above middle school education.
With respect to the pre-post test, tests were conducted involving (1) word retrieval, (2) subjective communication ability, and (3) intervention satisfaction to investigate the effects of the intervention.In the pre-test, the baseline of word retrieval and subjective communication were measured.The post-test was the same as the pre-test, but a satisfaction questionnaire was added to the intervention group to confirm satisfaction with the intervention.Among these tests, the test of subjective communication ability was a self-report questionnaire.Thus, both the pre-and post-questionnaires were provided as home assignments.The pre-test questionnaire was completed by the participantt at home on the day of the pre-test, and the participant was then asked to take a picture of the questionnaire and send it to the researcher.The post-test questionnaire was completed by the participantthrough a telephone call with the researcher the day before the post-test, and the participant was asked to present the questionnaire on the day of the post-test.Except for the participant communication ability test, the other tests were conducted individually in an independent space and in total took approximately 45 min.The participants were fully informed about the test task before the start of the test.The researcher sat with the participants and recorded their responses.
The word retrieval was evaluated by dividing it into a confrontation naming task, generative naming task, and fill-in-the-blanks task, considering the task type.A short form of the Korean-Boston Naming Test (S-K-BNT) 37 and a difficult naming test (DNT) 38 were conducted as confrontation-naming tasks.The S-K-BNT is a standardized test and DNT is currently undergoing standardization and will be published.In a previous study 39 , when comparing the characteristics of confrontation naming task according to the frequency of words in the normal elderly group and the MCI group, the frequency effect of words was higher in DNT than in K-BNT.The previous study has also shown that DNT showed statistically high correlation with K-MMSE and K-BNT.To measure the number of correct responses and reaction time, both naming tests were performed using the E-prime 3.0 program and tested through a 15.6-inch screen.The participants' responses were recorded using E-prime 3.0.The face-to-face naming test was analyzed in terms of the 'number of correct responses' and 'reaction time' .Regarding the number of correct responses, if an accurate target word was voluntarily produced based on the procedure manual, it was regarded as a correct response and one point was awarded.If an incorrect word was produced or a correct response was produced for an item that had already been provided in the past, it was considered an incorrect response.For reaction time, Praat, a speech analysis program was used and only when the correct target word was produced, the time from the moment the picture was presented, to the moment the participant responded verbally was analyzed.
For the generative naming task, semantic and phonemic fluency tasks were measured.These fluency tasks are sub-tests to assess the frontal lobe/executive function of the SNSB-II 34 .For the semantic fluency task, the semantic categories of 'animal' and 'supermarket' were used 40 .All participants' responses were recorded.Before starting the test, the researcher instructed as follows: "When I say 'Start.' quickly say as many animal names that come to your mind.You have to keep saying the names until I say, 'Stop.' The time limit is 1 min.Are you ready?Start." All participants' responses were recorded on a test record sheet.In the semantic fluency task, one point was awarded for a correct response only when words belonging to the relevant category (animals/supermarkets) were correctly spoken among the number of words spoken in one minute.Repeated words or those that did not www.nature.com/scientificreports/fall into the particular category were excluded from the score.When words from the superordinate and subordinate concepts were produced together (e.g.bird, goose, cuckoo, dove), only words from the specific subordinate concept (e.g.goose, cuckoo, dove) were included in the score, and words from the superordinate concept (e.g.bird) were excluded.In the phonemic fluency task, ' ,' ' ', ' ' were evaluated.Before starting the test, the researcher instructed the participants as follows: "This time, if I tell you a certain letter, please say as many words that start with that letter.For example, if I say, 'Tell me a word that starts with the letter ∟,' you can answer something like , , '. .Subsequently, to verify whether the participants understood the instruc- tions, they were asked to provide one or two examples.The researcher instructed as follows: "If you are ready, we will start.Say as many words that start with the letter ' ' ' ' as quickly as possible".After the "start" instruction, the test began.All participants' responses were recorded on a test record sheet.Correct responses were awarded one point.When the participantrepeated a word or produced a word that did not start with the corresponding phoneme or produced a proper noun such as a person's name or city name, the score was not awarded.For derivative words, only the first response was considered correct.The Probe test is a 'fill-in-the-blank' task and has the same format as the workbook.When the content validity was evaluated for three SLPs who obtained doctorate degrees in speech-language pathology, the mean value of all items was greater than the 4.3 point.For the fill-in-the-blanks test, two texts (one editorial and one newspaper article) that were not included in the workbook were presented.One text contained 10 fill-in-theblanks.Before starting the test, the researcher instructed as follows: "There are two texts, please solve as hard as you can.Unsolved problems can be left." Considering individual performance, no time limit was set, and the average task execution time was approximately 5-15 min.The synonyms of the target words to be filled in the blanks were regarded as correct answers.
For measuring subjective communication ability, the geriatric index of communicative ability (GICA) 41 , a standardized test tool, was used.The GICA consists of 18 items; however, in this study, only 12 items were used, excluding the auditory and voice areas that were not related to the intervention.The analysis used a Likert scale of 1-5 points, with a maximum score of 60 points; a higher score meant that there was no inconvenience in communication and it was maintained.
For measuring satisfaction with the intervention, the satisfaction questionnaire was administered to the intervention group.Based on the feedback of the workbook users, the researcher made 7 items and used them on a 1-5 point scale ('Very Much, Somewhat, Undecided, Not Really, Not at All').The researcher instructed as follows, "Please select the score that corresponds to the items asking about your satisfaction with the workbook training over the past 6 weeks." For the satisfaction questionnaire, the maximum score was 35 points, with higher scores indicating higher satisfaction with the intervention.The detailed items are listed in Table 2.

Statistics
SPSS (version 25.0) was used for the statistical analyses of the data.A repeated two-way analysis of variance (ANOVA) was performed to examine whether there was a significant intervention effect (p < 0.05) in terms of word retrieval and subjective appeal according to the group before and after the intervention.For the post-hoc analysis according to the main effect, a paired-sample t-test of the corresponding sample was performed.To control for type I error across multiple testing, the significance probability was corrected with Bonferroni correction.Since a paired t-test performed twice for each variable, the significance level has been revised to 0.025.

Ethics approval
This study was performed in line with the principles of the Declaration of Helsinki.Approval was granted by the Ethics Committee of Institutional Review Board of Samsung Medical Center (#2020-03-017-003).

Consent to participate
All the participants provided informed consent before participation.

Changes in naming ability according to intervention
The repeated two-way ANOVA revealed that there was an interaction effect (F (1, 97) = 6.567, p = 0.012) according to the group × test period in the number of correct responses to the S-K-BNT, and the main effect (F (1, 97) = 5.086, Table 2. Satisfaction questionnaire items.I think it has helped prevent dementia www.nature.com/scientificreports/p = 0.026) according to the test period occurred, and there were no differences between groups (F (1, 97) = 0.643, p = 0.425).Regarding the paired t-test for post-test according to the test period, the post-score of the intervention group significantly increased compared to the pre-score of the S-K-BNT (t = − 3.000, p = 0.004).Since there was no significant difference in the control group (t = 0.260, p = 0.796), the effect was only observed in the intervention group.The number of correct responses of DNT had no interaction effect (F (1, 97) = 1.604, p = 0.208) according to the group × test period, and there was no difference between groups (F (1, 97) = 0.478, p = 0.491).However, the main effect according to the test period (F (1, 97) = 26.251,p < 0.001) was significant.As a result of the paired sample t-test for the test period, both the intervention group (t = − 4.229, p < 0.001) and the control group (t = − 2.954, p = 0.005) significantly increased the post-score compared to the pre-score.The reaction time of DNT had no interaction effect (F (1, 97) = 0.037, p = 0.847) according to the group × test period, and there was no difference between groups (F (1, 97) = 1.371, p = 0.244).However, the main effect according to the test period was significant (F (1, 97) = 42.581,p < 0.001).As a result of the paired sample t-test for the test period, both the intervention group (t = 4.114, p < 0.001) and the control group (t = 5.287, p < 0.001) significantly increased the post-score compared to the pre-score.In the reaction time of S-K-BNT (F (1, 97) = 0.583, p = 0.447), there was no interaction effect according to the group × test period, and there was no difference between groups (F (1, 97) = 0.104, p = 0.748).However, the main effect according to the test period was significant (F (1, 97) = 9.161, p = 0.003).As a result of the paired-samples t-test for the test period, there was no effect in the intervention group (t = 1.560, p = 0.125), and an effect was found only in the control group (t = 2.757, p = 0.008).
In the semantic fluency task on generative naming, an interaction effect (F(1, 97) = 17.214, p < 0.001) according to the group × test period and a main effect (F(1, 97) = 4.10, p = 0.046) according to the test period were observed; however, there was no difference between the groups (F(1, 97) = 1.729, p = 0.192).In the paired t-test for post-analysis according to the test period, the intervention group showed a significant increase in the postscore compared with the pre-score of the semantic fluency task (t = − 4.916, p < 0.001).However, there was no significant difference in the control group (t = 1.359, p = 0.180).Moreover, in the phonemic fluency task, an interaction effect (F(1, 97) = 43.755,p < 0.001) according to the group × test period and a main effect (F(1, 97) = 25.369,p < 0.001) according to the test period were observed.However, there was no difference between the groups (F(1, 97) = 3.124, p = 0.080).In the paired t-test for post-analysis according to the test period, the intervention group showed a significant increase in the post-score compared to the pre-score of the phonemic fluency task (t = − 7.480, p < 0.001).However, there was no significant difference in the control group (t = 1.265, p = 0.212).
In the fill-in-the-blank task analysis, which is a probe test, an interaction effect (F (1, 97) = 13.198,p < 0.001) according to the group × test period and a main effect (F (1, 97) = 42.340,p < 0.001) according to the test period were observed; however, there was no difference between the groups (F( (1, 97) = 0.463, p = 0.498).In the paired t-test for post-analysis according to the test period, the intervention group showed a significant increase in the post-score compared to the pre-score of the prove test (t = -6.771,p = < 0.001).There was no significant difference in the control group (t = 2.175, p = 0.035) (adjusted significance level = 0.025).Table 3 presents the number of correct responses and reaction times for each group according to the word retrieval task and test period.

Changes in subjective communication ability scales according to intervention
In the repeated two-way ANOVA to examine whether there was a significant difference in the GICA according to the intervention, the interaction effect according to the group × test period (F (1, 97) = 1.771, p = 0.186), the difference between groups (F (1, 97) = 1.586, p = 0.211), and the test period (F (1, 97) = 0.008, p = 0.929), there were no main effects.Table 3 shows the descriptive statistical results of the GICA according to intervention.

Discussion
In this study, self-intervention training for naming using newspaper media was conducted for six weeks (30 sessions) for adults in the pre-clinical stage of dementia.Before and after the intervention, (1) word retrieval, (2) subjective communication, and (3) intervention satisfaction were compared.
The first major result of this study was that in terms of word retrieval, intervention effects were observed in the probe test (fill-in-the-blank) as well as in the confrontation naming (S-K-BNT) and generative naming (semantic and phonemic fluency) tasks.It is thought that the improvement in confrontation naming ability was due to the characteristics of the group related to the cause of difficulty in word retrieval.The SCD group frequently experiences a tip-of-the-tongue phenomenon 24 .If we explain the reason for the tip-of-the-tongue phenomenon based on the transmission deficit hypothesis, adults with SCD have no problem accessing the semantic system.However, the network connecting the semantic system to the phonological system is weakened causing word retrieval failure.In the case of the MCI group, the cause of the decline in word retrieval ability is www.nature.com/scientificreports/unclear; howeve, according to general hypotheses, naming defects result from the damage to semantic memory itself 42 , damage to the process of accessing semantic memory rather than damage to semantic memory itself 43 , or damage to the retrieval of appropriate words corresponding to semantic features from the lexical system 44 .The preclinical stage of dementia group in this study explained the correct meaning of the target word during the pre-post tests, or "I can't remember the word quickly, although this meaning should be included here."frequently complained.Therefore, the participants included in this study have difficulty finding and retrieving suitable words from the vocabulary system rather than the loss of semantic memory itself.Therefore, the performance on the confrontation-naming task increased as the semantic-lexical and phonological systems were strengthened while implementing fill-in-the-blank training using context.The observed intervention effect in the generative naming task may be related to the characteristics of the tasks used in training and the similarity of the cognitive-linguistic processing processes between tasks.Generative naming is a task of retrieving vocabulary corresponding to the presented semantic category (e.g.animals) or exploring vocabulary corresponding to a given phoneme (e.g. ).To solve the 'fill-in-the-blanks", attention is required to read the text to the end, and reasoning is required to grasp the context before and after and infer the appropriate meaning, to enter the blank while utilizing background knowledge.After inferring the meaning, the semantic-lexical system should be activated to find the vocabulary that corresponds to that meaning.In Korean, the postpositional particle behind the word varies depending on the phonetic characteristics of the word (e.g., If there is a final syllable in a word, the nominative particle is ' ' ' ' , and if there is no final syllable, ' ' ' ' is used).Therefore, when selecting the vocabulary, the participants have to consider the postpositional particle after the blank.In addition, to find the most appropriate vocabulary to fill in the blank, it is necessary to approach the semantic-lexical system and repeat the process of exploring and modifying the grammatical form of the vocabulary.In other words, the role of the frontal lobe along with the functions of other lobes can crucial since the executive function that integrates various cognitive subfunctions must be sufficiently activated to perform the 'fill-in-the-blank' task.If the workbook user cannot find an appropriate word to fill in the blank, they will turn over the page and check the semantic and phoneme cues.After recalling the semantic cue in the brain, it goes through the process (phonological-lexical system) of finding a target word using a phoneme cue presented as another cue.In this process, the frontal lobe will be activated since working memory and phonological-lexical systems rely more on word retrieval.For solving the letter completion problem (e.g.Use suggested letters to complete words related to animals) presented as an additional task during the intervention, it is necessary to recall whether the presented word falls under the category of 'animal, ' look at the phoneme presented, and then search for the 'animal vocabulary' that matches the phoneme.This is similar to the process of retrieving appropriate words by using semantic and phonemic clues when words can not be clearly retrieved in the 'fill-inthe-blank' task.An additional task included in the workbook, the initial consonant word task (e.g., write down at least 10 words that begin with ' ' ' ') requires that the process of combining vowels and final consonants with the presented two consonants be repeated to retrieve meaningful words that match the phoneme.The reason for a greater degree of improvement in the generative naming task than in the confrontation naming task may be due to the difference in cognitive abilities used when performing the two tasks.For confrontation naming, visual information is provided, unlike the workbook fill-in-the-blank training.When trying to name an object, its visual properties are first judged through a visual analysis of the size, shape, and color of the picture.Subsequently, objects are recognized by integrating visual information and matching it with long-term memory.In the semantic system stage for the recognized object, the concept of the use and characteristics of the object stored owing to the accumulation of personal experience or knowledge are used to identify the intrinsic properties of the object.Subsequently, the word in the lexicon and the meaning of the object are connected.At this stage, a specific meaning and appropriate vocabulary are selected [45][46][47] .Confrontation naming is important for visual recognition and generally depends on linguistic semantic memory.In contrast, the fill-in-the-blanks task included in the workbook requires the ability to generate vocabulary by inferring appropriate meanings without reference and goes through more complex semantic processing than the confrontation naming task.The letter completion task and the initial consonant word task are also related to the activation of the frontal lobe since they involve complex processing and multifaceted cognitive functions such as attention, short-term memory, the phonological-lexical system, and the semantic-lexical system.Therefore, since the tasks included in the workbook consisted of tasks that required more activation of the frontal and temporal lobes in terms of brain function activation, the posterior score may have improved significantly in the generative naming task.
Interestingly, the score of the group that received the intervention improved in the generative naming task, while the score of the group that did not receive the intervention showed lowered pattern in the post-test.These results suggest that for the group that did not receive the intervention, it is possible that they gradually showed difficulty in retrieving words over time.In addition, phonemic fluency improved to a greater extent than semantic fluency within the generative naming task, and differences in the degree of performance improvement were observed according to the subtype.For generative naming, it is known that search strategies and reliance on systems differ depending on subtypes 48 .Phonemic fluency requires a relatively 'phonological' search, while semantic fluency requires a familiar 'semantic' search.As mentioned above, the group including those in the preclinical stage of dementia generally had no problems accessing the semantic system whereas they faced problems with tasks associated with the network that connects the lexical and phonological systems.Therefore, the score might have improved more in the phonemic fluency task due to the effect of the interventions (letter completion task according to semantic category and word generation task using initial consonants) which strengthened the level of the phonological-lexical system.
The second major finding of this study was that no significant change in subjective communication ability was observed in either group.GICA is a questionnaire composed of items that can evaluate overall communication skills such as 'attention/memory, language comprehension/production, and communication efficiency'(e.g.'I forget what I was trying to say while I was talking, ' 'It is difficult to understand when I hear long, complex words').It is possible that the intervention did not have a significant effect on the communication ability experienced in daily life, or that there was no significant difference in the intervention group since the items in the GICA were not directly related to word retrieval.
As the third major finding of this study, a high rate of positive responses was observed in the satisfaction of the participants who received the intervention.The sum of the percentages of positive responses with 'very much' (5 points) and 'somewhat' (4 points), is as follows: "'1.I am generally satisfied with the workbook homework (82.8%)' , '2.My self-confidence has improved (74.3%)' , '3.The will to live has increased (74.3%,)' , '4.Positive thoughts (hope) and emotions (happiness) increased (68.5%)' , '5.It gave me an opportunity to check about the problem of not remembering words by myself (85.7%)' , '6.I have the motivation to pursue other studies (74.3%)' , '7.I think it has helped prevent dementia (85.7%).In addition, workbook users said, "I had nothing to do at home, but I had a good time solving the workbook.", "My memory seems to improve.", "It was difficult initially to read newspaper articles, but subsequently, the solving time shortened, and the content of the article became interesting, so I wanted to continue solving it."The majority of people responded positively to all the items, confirming that they were satisfied not only with the workbook task but also with various aspects of life through the intervention of 'filling in the blanks in editorial and newspaper articles' .
In summary, improvements in word retrieval abilities were observed after the intervention, and consequently, satisfaction with various aspects of life increased.This is thought to be due to the activation of the frontal and temporal lobes through this intervention, consisting of training to strengthen the lexical-semantic and phonological-vocabulary systems.Until now, no study has examined the word retrieval ability of the cognitive impairment risk group using a fill-in-the-blanks task based on the contents of mass media.Therefore, this is the first intervention study to use a newspaper editorial workbook, and it is noteworthy to investigate the efficacy of word finding through non-face-to-face learning without the restrictions of place and time.Especially, our findings provide the basis for the active application of this intervention method clinically to prevent dementia while showing the possibility of it being used as one of a new therapeutic alternative employing mass communication media in the era of pandemics such as 'COVID-19' .
The limitations of this study were as follows.The study does not investigate SCD and MCI separately.The main purpose of the study was to investigate the effect in pre-dementia cases, and we considered SCD and MCI participants as one group in accordance with the research purpose.To explore the group difference between SCD and MCI, we have already conducted an analysis on 34 SCD participants (17 in both the intervention and control group) and 36 MCI participants (18 in both the intervention and control group) in a preliminary study 49 .

Table 1 .
Participants' characteristics.K-MMSE Korean version of mini-mental state examination, SGDS short form geriatric depression scale.

Table 3 .
Comparison of word retrieval ability and old age communication ability scale according to pre-post test.S-K-BNT short-Korean-boston naming test, DNT difficult naming test.***Significant difference between Intervention and Control group with *p < 0.05, ** p < 0.01, *** p < 0.001.